IBT Staff Reporter

A big U.S. exchange operator said on Tuesday there was no smoking gun to explain Thursday's mysterious market plunge, while regulators and exchanges solidified plans to adopt circuit breakers.

U.S. payroll numbers may be starting to improve, but leaders from a cross-section of manufacturing and transportation companies said this week they remain reluctant to hire too many workers too soon.

U.S. hirings touched their highest level in 15 months in March, while job openings also rose, according to a government report on Tuesday that confirmed a recovery in the labor market was gaining traction.

Hong Kong received an opening bid of HK$2.876 billion ($370 million) in an auction for a residential site on Tuesday, the first land sale since the government moved to crack down on speculation in the housing market.

Russia said Tuesday, the possible merger of the Russian energy giant Gazprom and Ukraine's Naftogaz has no bearing on the South Stream project. Russian Energy Minister Sergey Shmatko said, We do not relate these two issues. South Stream is an issue of principle for us, a strategic entry to direct supplies for European buyers.

OPEC on Tuesday said it's forecast for global oil demand remained unchanged at 1.1 percent or by 0.9 million barrels per day. In its monthly oil market report, OPEC said although the economic recovery shows signs of improving momentum, important risks remain that could impact demand growth expectations for this year.

The last recession forced the auto industry to slash costs, shutter factories, tear up contracts and rely on government funding.

Platinum and palladium markets received some good news this week with the auto sales zooming in India and China. Platinum and palladium, two metals used in the high end car exhausts to cut pollution, prices depend mostly on the auto sales across the globe. With India and China reporting huge car sales in April, the prices of platinum and palladium are set to gain from this news.

Sales of Mercedes-Benz brand vehicles rose 15.3 percent to 93,100 units in April, the third German luxury carmaker to confirm that a recovery in demand continued over last month.

The largest U.S. banks would be required to submit to regulators plans for their dismantling in times of severe distress, and securitizations with higher underlying standards would get federal protection, under two proposals to be considered by the Federal Deposit Insurance Corp on Tuesday.

Federal Reserve Chairman Ben Bernanke on Tuesday described the Greek debt crisis as a European problem but one that could have hit U.S. banks if left unattended, a senior Republican senator said.

U.S. consumer confidence improved in May, boosted by the perception that the worst was over in terms of job losses and helped by optimism associated with earlier gains in the stock market, a report released on Tuesday showed.

U.S. stocks managed modest gains at midday on Tuesday, recovering from early losses on strength in the biotech sector after Gilead Sciences unveiled a large stock-buyback program.

Germany's cabinet approved the biggest national contribution to a $1 trillion emergency package intended to stabilize the euro, as global markets sobered up after Monday's euphoric rally.

U.S. stocks slipped on Tuesday, easing from the previous session's hefty gains as concerns lingered about how Greece will get its budget deficit under control.

U.S. policy-makers must not wait too long to raise interest rates with inflation unlikely to stay at low levels as the economic recovery picks up steam, a top Federal Reserve official said on Tuesday.

American International Group Inc Chief Executive Robert Benmosche told employees he is confident a $35.5 billion deal to sell its Asian life insurance unit would move forward, a source familiar with the matter said.

Small U.S. business owners are slightly less pessimistic about their outlook, and in the face of continuing weak sales do not plan to boost capital spending or employment, a monthly survey of small businesses showed.

(Reuters) - A cancer report that concludes Americans are under constant assault from carcinogenic agents has heartened activists, who hope that finally government and policymakers will pay attention to their concerns.

Europe's travel industry is counting the cost of air traffic disruption caused by a volcanic ash cloud which forced thousands of flights to be canceled and is braced for more stoppages this month.

(Reuters) - Low condom use, needle sharing and a rise in casual sex and prostitution may unleash an HIV epidemic in the Philippines, according to a new study.

(Reuters) - The evidence is stronger than ever that pollution from industry, traffic and power generation causes strokes and heart attacks, and people should avoid breathing in smog, the American Heart Association said on Monday.

People working 10 or 11 hours a day are more likely to suffer serious heart problems, including heart attacks, than those clocking off after seven hours, researchers said on Tuesday.

New York City's recession likely will linger for the average resident, though technical indicators suggest both the nation and the city have turned the corner, the Fiscal Policy Institute reported on Tuesday.

U.S. prosecutors have accused ABN Amro, now largely part of Royal Bank of Scotland , of turning a blind eye to U.S. laws, using special procedures to bypass U.S. sanctions against Cuba, Iran and other countries.

Some of the world's top advertising and marketing chiefs will meet in Moscow this week to exchange ideas on the best ways for the $450 billion industry to capitalize on a still fragile economic recovery.

Market watchdogs and six major exchanges agreed new safeguards were needed to curb trading in plunging markets, an effort to address last Thursday's mysterious market free fall.

Senior executives from NYSE Euronext, Nasdaq OMX Group Inc and CME Group Inc will testify to a congressional panel on Tuesday on last week's shock sell-off in the stock markets, according to a witness list obtained by Reuters.

The euro fell on Tuesday and stocks retreated as a relief rally ignited by a $1 trillion plan to contain Greece's debt crisis ran out of steam, while doubts on how the country will cut its budget deficit persisted.